The 16:8 diet has been one of the most popular diet plans we've seen in years - and with good reason.
The 16:8 plan – also called the 8-hour diet – is an easier and more consistent way of fasting that avoids heavily calorie restricted days found in other popular intermittent fasting plans like the 5:2 diet or Fast 800 calorie diet.
Studies have shown that intermittent fasting can have benefits on both your body and mental health, as well as being a very powerful tool for weight loss.
A famous fan of the 16:8 intermittent fasting plan is Hollywood icon Jennifer Aniston. In an interview with the Radio Times, Jennifer revealed that she’s a big fan of intermittent fasting in general but specifically this plan. “I do intermittent fasting, so no food in the morning.” She said, “I noticed a big difference in going without solid food for 16 hours.”
What is the 16:8 diet?
The 16:8 diet is a type of intermittent fasting where you break each day into two parts – a 16 hour stretch and an 8 hour period. For 16 hours every day, you consume nothing but water, coffee, tea and other unsweetened drinks. Then for the other eight hours of the day, you can eat all your meals and snacks.
The 16 hour stretch sounds like a long time, but if you’re getting enough sleep, you should be asleep for about half of that time.
Sports Scientist Harry Aitken tells GoodtoKnow, “Intermittent fasting is a dietary technique in which all food is consumed within a relatively small window of time. Fasting is going for a significant period of time without eating, and intermittent fasting simply brings in a small window of time where you are able to eat.
“Intermittent fasting has been popularised and studies have gone on to confirm that it leads to weight loss and fat loss.”
The 16:8 diet stems from the book 8 Hour Diet by author David Zinczenko and editor-in-chief of Men’s Health Peter Moore, who suggested that a longer fasting time between eating gives the body the time it needs to process the food and burn away extra fat.
How does the 16:8 diet work?
The 16:8 diet works on an hourly basis. So each day you can eat within an 8 hour time frame and fast for the remaining 16 hours. The best part? You don’t have to restrict your calories when eating during the 8 hour window. As long as you eat healthily in your 8 hour time frame, you’ll see the weight drop off.
Experts say that the 16.8 diet restricted schedule gives our bodies the chance to process the nutrients stored in foods and burns away calories. Plus, you won’t go hungry like you do on those two fasting days on the 5:2 either.
As Tom Jenane, nutrition and fitness expert explains, “The 16:8 diet is a brilliant form of intermittent fasting that has proven results in a number of cases.”
As well as Jennifer Aniston, other Hollywood names who have seen success after following the 16:8 diet include Hugh Jackman, who reportedly used the diet to get in shape for his Wolverine films and actress Jennifer Love Hewitt.
When can I eat on the 16:8 diet?
You can pick an 8 hour window to suit your day. So, for example it could be between 10am – 6pm or 11am – 8pm and so on. Plus, you can still drink tea and coffee outside of those hours too, although because of the benefits of drinking water you are also encouraged to stay as hydrated as possible.
Most people choose to fast through the night, and opt to eat their first meal at about 11am or in the middle of the day.
Tom says, “The most common hours adopted for the eating period is 12 till 8pm. The reason for this is because people aren’t normally that hungry in the morning, you don’t want to be consuming too many calories during the evening and this allows us to eat our lunch and dinner as well as a healthy snack.”
What can you eat on the 16:8 diet?
This diet isn’t suggesting you cram all the food you can into 8 hours. You need to make sure you’re eating a balance of fat busting and health boosting foods. Experts have suggest making sure you get a balance of lean meat, eggs, dairy, vegetables, nuts and beans each day.
Tom said, “Many people fail the 16:8 diet by packing in too many calories into the 8 hour period, often trying to get some in before the 8 hours ends. You should still be following a strict diet with a complete nutritional breakdown, to ensure you are consuming a targeted number of calories, not to mention macro nutrients and ensuring you’re not consuming too much sugar.”
Try sticking to the following foods on the 16:8 diet:
- Whole grains: Ones like rice, oats, barley, wholegrain pasta and quinoa will keep you fuller for longer.
- Protein: Meat, poultry, fish, eggs, nuts and seeds will keep you full.
- Fruit: Apples, bananas, berries, oranges and pears will offer good vitamin sustenance.
- Vegetables: Broccoli and leafy greens are especially good for making sure you’re eating enough fibre.
- Healthy fats: Olive oil, coconut oil, avocados.
How much weight can you lose on 16:8 diet?
To lose weight on the 16:8 diet, it’s important to match the fasting with healthy eating and exercise. If done so correctly, there’s a typical weight loss of around seven to 11 pounds over a ten week period. This is according to a review of 40 different studies published in Molecular and Cellular Endocrincology who found that on average, someone weighing just over 90kg would lose 5% of their total body weight in the ten week period.
A 2018 study published in the Journal of Nutrition and Healthy Eating revealed that the 16:8 diet plan can help people lose weight, without having to count calories as the 8-hour fast produces the same kind of calorific restriction and weight loss.
However, whether there’s a distinct weight loss advantage achieved on the 16:8 diet compared to other diets remains to be seen. Some studies have demonstrated that there’s almost no difference between people who do intermittent fasting compared those who count calories and cut back on unhealthy food.
How often should you do 16:8 intermittent fasting?
Unlike other intermittent fasting diets, each day of the 16:8 works independently to the other days. This means that you can do anywhere from one day of intermittent 16:8 fasting to seven days a week, depending on your goals and the advice from your GP.
Evidence differs, however, on whether it’s healthy to do intermittent fasting all the time for a number of reasons. While one study suggests that fasting helps your vital organs by giving metabolic functions a break, other research suggests the fasting can lead to an increased level of cholesterol and can lead to feelings of nausea, along with causing spells of low-blood sugar and dehydration.
Are there any health benefits to fasting?
For some looking to lose weight quickly for health-related reasons, fasting is a good (but intense!) way to go about it. As Eve Mayer, author of Life in the Fasting Lane
“Being overweight is a cause of many diseases, such as heart disease, stroke and cancer,” says Eve Mayer, author of Life in the Fasting Lane. “Losing weight increases high-density lipoprotein and lowers triglyceride levels, which helps reduce the risk of those same diseases.”
But the 16:8 diet is not just about losing weight.
Improved heart health
A study by New England Journal of Medicine has shown that regular fasting is linked with a longer life and lower incidence of heart failure in heart patients. Even just one day of fasting a month – when done over a lifetime – can have a profound effect on heart health.
A regular circadian rhythm
Your internal body clock regulates tiredness and alertness over a 24-hour period. Research suggests intermittent fasting may strengthen our body’s circadian rhythm, as overeating can cause interrupted sleep, therefore helping us to sleep better.
Reduce stress and improve mental health
The 16:8 diet help reduce cortisol levels (that means less stress!) and help reduce inflammation. Plus, since you won’t be dealing with hunger for two days a week, it’s better for your mental health.
Those who’ve tried the 16:8 diet say how much more productive they are during fasting hours, spending less time stressing over food and more time channelling their energy into other beneficial tasks throughout the day.
While it’s important to remember that what works for one person’s lifestyle won’t work for another, intermittent fasting with the 16:8 diet has given some people some real success – in all areas of life.
Before starting on any weight loss plan, it’s best to consult your GP who will be able to advise the best course of action for you.